He is the son of former Geelong player, Terry Callan.
Callan was selected by Geelong in the 2002 AFL Draft, under the father–son rule.
A small/medium-sized defender, Callan is renowned for his consistent displays of courage and bravery during the game, often backing into packs for marks or spoils.
Although he has proven himself as one of the better players for the club's VFL side for numerous seasons, he has struggled to get consistent games in the senior side for the Cats.
Looking for a more permanent role in a senior team, Callan was traded along with pick 66 to the Western Bulldogs on 9 October 2007 during the official trade week for the Bulldogs pick 62 in the national draft.